Differentially expressed genes in cultured aortic smooth muscle cells by cholesterol-loading

Differentially expressed genes generated by cholesterol-loading in the cult ure medium of aortic smooth muscle cells (SMC) were screened using the DDRT -PCR technique in order to identify the genes that are possibly involved in the pathogenesis of atherosclerosis in the artery. Twenty-eight genes were initially isolated and three differentially expressed cDNAs were finally s elected by Northern blot analysis. All three cDNAs were up-regulated (desig nated CRGSM-1 through -3) by the cholesterol-loading, Upon nucleotide seque ncing and homology search in the databases, the first cDNA (CRGSM-1) had a high homology (97%) with the corresponding segment of the acyl-CoA syntheta se II gene from rat brain, which participates in fatty acid synthesis. The second one (CRGSM-2) had a high homology (91%) with a part of Mus musculus (mouse) LIM protein 1, and with human skeletal muscle LIM-protein 1 genes ( 80%) and the third gene (CRGSM-3) had no significant homology match in the database. A full size cDNA isolated from the cDNA library of rat aortic smo oth muscle cell using the CRGSM-2 as a probe was identified to have a high homology with muscle LIM protein (MLP), The isolated cDNA contained a segme nt of DNA that encodes for a zinc-finger motif and two LIM domains. Protein s bearing the LIM domain, defined as a unique double zinc-finger structure associated with a subclass of proteins involved in the determination of-cel l identity, cell differentiation and control of cell growth, have previousl y been suggested to play an important role in the pathogenesis of atheroscl erosis by others.